运行brew install dpkg后，dpkg已成功安装;但是，就像下面的自制软件说的那样，无法安装或卸载任何软件。
==> Caveats
This installation of dpkg is not configured to install software, so
commands such as `dpkg -i`, `dpkg --configure` will fail.
完整安装输出：
MacBook-Air:~ james$ brew install dpkg
==> Installing dependencies for dpkg: gnu-tar, xz
==> Installing dpkg dependency: gnu-tar
==> Downloading https://homebrew.bintray.com/bottles/gnu-tar-1.28.yosemite.bottle.2.tar.gz
######################################################################## 100.0%
==> Pouring gnu-tar-1.28.yosemite.bottle.2.tar.gz
==> Caveats
gnu-tar has been installed as "gtar".
If you really need to use it as "tar", you can add a "gnubin" directory
to your PATH from your bashrc like:
PATH="/usr/local/opt/gnu-tar/libexec/gnubin:$PATH"
==> Summary
/usr/local/Cellar/gnu-tar/1.28: 13 files, 1.6M
==> Installing dpkg dependency: xz
==> Downloading https://homebrew.bintray.com/bottles/xz-5.2.1.yosemite.bottle.tar.gz
######################################################################## 100.0%
==> Pouring xz-5.2.1.yosemite.bottle.tar.gz
/usr/local/Cellar/xz/5.2.1: 59 files, 1.7M
==> Installing dpkg
==> Downloading https://homebrew.bintray.com/bottles/dpkg-1.17.25_1.yosemite.bottle.tar.gz
######################################################################## 100.0%
==> Pouring dpkg-1.17.25_1.yosemite.bottle.tar.gz
==> Caveats
This installation of dpkg is not configured to install software, so
commands such as `dpkg -i`, `dpkg --configure` will fail.
==> Summary
/usr/local/Cellar/dpkg/1.17.25_1: 246 files, 5.3M